Digit amputation in small ruminants

Digit amputation is a relatively common salvage procedure carried out in cattle (Desrochers et al, 2008), but it can equally be applied to small ruminants. This review is significantly based on the authors' own experience of performing this surgery in first opinion practice, as literature on the subject is limited.

In cattle digit amputation is indicated for septic pedal arthritis (infection of the distal interphalangeal joint) (Pejsa et al, 1998; Desrochers et al, 2008), pedal osteitis (infection of P3), toe necrosis (Blowey et al, 2011), non-healing solar and wall ulcers (Blowey et al, 2011), and indeed any painful, untreatable problem localised to the distal digit.

These same indications occur in small ruminants, but their relative frequency is different. The most common reason for digit amputation in sheep is septic pedal arthritis (Scott, 1995; Lovatt, 2012). This may originate from extension of infection from the interdigital space, from a penetrating wound affecting the distal interphalangeal joint or from infection elsewhere in the deep tissues of the foot. These cases present with extreme lameness (grade 3/3), and with swelling of the foot above the coronary band (Figure 1). This swelling is asymmetrical, with the affected digit being noticeably enlarged relative to the normal side. In some cases, especially chronic ones, there may be a discharging tract above the coronary band (Winter, 2004). This may be situated at the abaxial aspect of the coronary band, but the authors have also seen sinuses in the interdigital space, or at the caudal aspect of the foot. Unfortunately, affected animals often have a history of chronic lameness with multiple failed antibiotic treatments by the farmer (Scott, 1988; Lovatt, 2012). Where the condition is chronic there is often hair loss around the coronary band (Winter, 2004).